Templating Aerogels for Tunable Nanoporosity
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The engineering of porosity, particularly at the meso-level, is expected to be of great scientific and technological significance in the 21st century where advances in nanoscience and technology are projected to catalyze major breakthroughs in biosciences and materials.
Aerogels are a class of highly porous buoyant materials that find use or show promise in many key products such as catalysts, thermal insulators, chemical adsorbers, sensors, fuel storage, energy absorbers, and aero capacitors. They may be in the form of particles, thin films, fibers, or monoliths. Some of the remarkable properties for the aerogels are high porosity, large pore volume, high surface area, and very good morphological stability during heat treatment at high temperatures. Recent discovery of surfactant-templated pathways enables better control over the properties of the porous materials. The advantages of the templating include high porosity, tunable unimodal or multimodal nanoporosity, and directional control. The new evaporation-induced self-assembly method that enables production of aerogel-like materials using soft chemistry and lower pressures further expands the spate of products that are possible in economically promising fashion. This porous structure can be further functionalized through doping and impregnation to host catalytic sites, conducting phases, or magnetic phases.
This review aims to address the issues of preparation of templated gels, removal of the solvent and template material, and subsequent functionalization of the surfactant-templated aerogels to further tune the porous structures.